Stereo camera systems or stereo front-camera systems (SFK systems), in which two camera modules, generally parallel to one another, which detect the roadway area in front of the vehicle through the windshield, are mounted in the motor vehicle, are used for classifying objects on a roadway, for assigning attributes to objects, and for determining the distance of objects from a motor vehicle. For the required accuracy in determining the distance of contours in the stereo video image for distances greater than/equal to 40 m, the relative positions of the contours must be resolved into the micrometer range on the electronic imaging chips. To do this, the relative positioning of the two cameras to one another must be effected in a very precise and stable manner; in addition, the position of the camera system with respect to the vehicle must also be defined in a precise and stable manner at any given time.
For this purpose, a support, for example a diecasting of aluminum or magnesium, is mounted in the roof structure of the vehicle, which accommodates the camera modules in accommodating regions and the control and analyzing electronics in a central region. In addition, the support seals the optical path of the camera against soiling and scattered light and permits simpler installation of the camera system in the process of manufacture.
In such conventional stereo camera systems in a motor vehicle, however, changes in spacing of the camera modules with respect to one another and with respect to the motor vehicle are a problem. Changes in spacing that take place slowly, due for example to thermal expansion of the support, may be compensated for by readjustment of image correction data. For this purpose, the required parameters may be detected by a separate sensor system or may be determined directly from the image processing system.
On the other hand, brief changes in spacing, which may for example be injected into the support by vibrations, can generally not be corrected. The support system must therefore have a high degree of rigidity to all vibrations under the video frequency—generally 30 Hz–100 Hz, depending on the system. However, more rigid design of the support generally results in higher manufacturing costs and a higher total weight and yet fails to provide sufficient suppression of vibrations.